When compared to conventional direct seeding, pot seedling transplanting has the following major advantages: growth periods of vegetables can be shortened, crop arrangement is facilitated, land utilization is improved, and economic income is increased. Transplanted pot seedlings have a strong root system and consistent flowering and maturation, which can facilitate subsequent stages such as management and harvesting. Therefore, plug seedling cultivation and pot seedling transplanting have become increasingly popular among vegetable producers and flower producers. However, because no suitable auxiliary machines are available, plug seedling cultivation and pot seedling transplanting have been labor intensive industries for a long time, where the labor cost accounts for over 50% of the total production cost. Manual transplanting has high labor intensity, and the transplanting quality and work efficiency are so low that large-area transplantation can hardly be implemented. As a consequence, the production scale is small, the production efficiency is low, and the development of related crop production in China is restricted. However the mechanized transplanting can reduce the production cost, improve the work efficiency and transplanting quality. Therefore, there is an urgent need for the development of a system that implements the mechanization of pot seedling transplanting work.
A pot seedling transplanter includes two key systems: a seedling feeding system and a planting system. The purpose of the seedling feeding system is to deliver a pot seedling into a planter. In an existing semi-automatic transplanter, a rotary holding cup structure is usually used for a seedling feeding system. Only one pot seedling can be fed at a time, and operations cannot be discontinuous. As a result, the labor intensity is relatively high and operators become tired easily, so the transplanting speed is relatively slow (the transplanting speed is usually about 40 seedlings per minute). A fully-automatic transplanter has an automatic seedling feeding system, which does not require manual seedling feeding, and has a high transplanting speed. However, the fully-automatic transplanter has a relatively complex mechanism system and a very high cost, it is not suitable for medium-scale and small-scale users. In the invention patent (application No. 201210317407.8) of an automatic seedling picking and feeding mechanism for plug seedling transplanter, an automatic seedling picking and feeding mechanism for plug seedling transplanter was disclosed, including a displacement mechanism, a support stand, a slide rod, a connecting-rod mechanism, and a seedling clamping mechanism. The support stand is installed on the displacement mechanism so as to implement position switching of the support stand between a seedling picking action and a seedling feeding action. One end of the slide rod is inserted in a slide sleeve movable inside a slide groove on the support stand, and the other end of the slide rod is connected to the seedling clamping mechanism. The displacement mechanism is used to implement switching of the seedling clamping mechanism between a seedling picking procedure position and a seedling feeding procedure position. The connecting-rod mechanism is used to control the rotation of the slide rod and the seedling clamping mechanism and implement closing and opening of a seedling clamp. The apparatus has a relatively complex structure and a relatively high production cost, and the seedling clamping mechanism of the apparatus cannot precisely position a pot seedling in a seedling clamping process, which results in the loss of seedlings. In the invention patent (application No. 2011101335051) of a mechanical seedling feeding transplanter, a mechanical seedling feeding mechanism which can replace manual operation is disclosed. Multiple pot seedlings can be placed into a mechanical seedling feeding system each time, with the control of electric-control system, the seedling feeding mechanism can drop seedlings automatically by using delivery cups. Thereby this mechanism improves the speed and efficiency of transplanting work, meanwhile the production cost is reduced. However, the seedling feeding mechanism has a complex design and a relatively large quantity of parts.